This invention relates in general to electrical machines and in particular to a ring wound stator of a permanent magnet machine.
The most important dimension for a permanent magnet electrical machine is the magnetic air gap between the surface of the rotor's magnet and the inner diameter of the stator's flux collector ring. An increase of flux density in the magnetic air gap will improve the operating performance of the machine, and it can result in a smaller, lighter machine. The higher flux density causes a greater torque reaction when the machine is operated as a motor, and it results in higher output rating when the machine is operated as a generator.
Air gap flux density can be increased by utilizing permanent magnets with higher energy product in the rotor.